Drug-Drug and Drug-Food Interactions

Question 1

Describe Pharmaceutical interactions

Answer 1

Either physical or chemical; Will lead to either an additive or antagonistic effect

Question 2

What can interactions affect?

Answer 2

1. Absorption
2. Distribution
3. Metabolism
4. Excretion

Question 3

Discuss pharmacokinetic interactions on absorption.

Answer 3

Drugs can influence each other by

1. increasing gastric pH
2. Changing gastric emptying
3. Changing hepatic blood flow.

Question 4

How can drug’s affect each others distribution?

Answer 4

1. Changing blood flow

2. Binding to plasma proteins

Question 5

Discuss Metabolism inhibition

Answer 5

A drug inhibits another drug resulting in:

1. Increased exposure (toxic)
2. Decreased exposure (lower efficacy)

Question 6

Differentiate Metabolism inhibition from induction.

Answer 6

It takes 2-3 weeks to make more enzymatic proteins for induction.

Question 7

Why are food-drug interactions important?

Answer 7

Food can change the bioavailability of a drug.

Question 8

Explain the relationship of vitamin K with Warfarin.

Answer 8

A diet with high vitamin K can impede warfarin (anticoagulant).

Question 9

Explain the relationship of Diurectics and a high sodium diet.

Answer 9

A high sodium diet can impede the action of diuretics, leading to high bp and edema.

Question 10

How can food change drug absorption?

Answer 10

1. Bile flow
2. GI pH
3. Gastric emptying

Question 11

Discuss charcoal-broiled foods, vegetables, and grapefruit

Answer 11

Charcoal-broiled foods and vegetables induce CYP450 1A enzymes. Grape fruit inhibits CYP450 3A4 (intestinal)

Question 12

Discuss the effects of cigarette smoke

Answer 12

Smokers metabolize drugs faster than nonsmokers due to enzyme induction.